/**
 ******************************************************************************
 *
 * @addtogroup PIOS PIOS Core hardware abstraction layer
 * @{
 * @addtogroup PIOS_FLASH Flash device handler
 * @{
 *
 * @file       pios_flash_w25x.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @author     PhoenixPilot, http://github.com/PhoenixPilot, Copyright (C) 2012
 * @brief      Driver for talking to W25X flash chip (and most JEDEC chips)
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "pios.h"

#ifdef PIOS_INCLUDE_FLASH

#include "pios_flash_jedec_priv.h"
#include "pios_flash_jedec_catalog.h"

#define JEDEC_WRITE_ENABLE        0x06
#define JEDEC_WRITE_DISABLE       0x04
#define JEDEC_READ_STATUS         0x05
#define JEDEC_WRITE_STATUS        0x01
#define JEDEC_READ_DATA           0x03
#define JEDEC_FAST_READ           0x0b
#define JEDEC_DEVICE_ID           0x9F
#define JEDEC_PAGE_WRITE          0x02

#define JEDEC_STATUS_BUSY         0x01
#define JEDEC_STATUS_WRITEPROTECT 0x02
#define JEDEC_STATUS_BP0          0x04
#define JEDEC_STATUS_BP1          0x08
#define JEDEC_STATUS_BP2          0x10
#define JEDEC_STATUS_TP           0x20
#define JEDEC_STATUS_SEC          0x40
#define JEDEC_STATUS_SRP0         0x80

enum pios_jedec_dev_magic {
    PIOS_JEDEC_DEV_MAGIC = 0xcb55aa55,
};

// ! Device handle structure
struct jedec_flash_dev {
    uint32_t spi_id;
    uint32_t slave_num;
    bool     claimed;

    uint8_t  manufacturer;
    uint8_t  memorytype;
    uint8_t  capacity;

    const struct pios_flash_jedec_cfg *cfg;
#if defined(FLASH_FREERTOS)
    xSemaphoreHandle transaction_lock;
#endif
    enum pios_jedec_dev_magic magic;
};

#define FLASH_FAST_PRESCALER PIOS_SPI_PRESCALER_2
#define FLASH_PRESCALER      PIOS_SPI_PRESCALER_4

// ! Private functions
static int32_t PIOS_Flash_Jedec_Validate(struct jedec_flash_dev *flash_dev);
static struct jedec_flash_dev *PIOS_Flash_Jedec_alloc(void);

static int32_t PIOS_Flash_Jedec_ReadID(struct jedec_flash_dev *flash_dev);
static int32_t PIOS_Flash_Jedec_ReadStatus(struct jedec_flash_dev *flash_dev);
static int32_t PIOS_Flash_Jedec_ClaimBus(struct jedec_flash_dev *flash_dev, bool fast);
static int32_t PIOS_Flash_Jedec_ReleaseBus(struct jedec_flash_dev *flash_dev);
static int32_t PIOS_Flash_Jedec_WriteEnable(struct jedec_flash_dev *flash_dev);
static int32_t PIOS_Flash_Jedec_Busy(struct jedec_flash_dev *flash_dev);

/**
 * @brief Allocate a new device
 */
static struct jedec_flash_dev *PIOS_Flash_Jedec_alloc(void)
{
    struct jedec_flash_dev *flash_dev;

    flash_dev = (struct jedec_flash_dev *)pios_malloc(sizeof(*flash_dev));
    if (!flash_dev) {
        return NULL;
    }

    flash_dev->claimed = false;
    flash_dev->magic   = PIOS_JEDEC_DEV_MAGIC;
#if defined(FLASH_FREERTOS)
    flash_dev->transaction_lock = xSemaphoreCreateMutex();
#endif
    return flash_dev;
}

/**
 * @brief Validate the handle to the spi device
 */
static int32_t PIOS_Flash_Jedec_Validate(struct jedec_flash_dev *flash_dev)
{
    if (flash_dev == NULL) {
        return -1;
    }
    if (flash_dev->magic != PIOS_JEDEC_DEV_MAGIC) {
        return -2;
    }
    if (flash_dev->spi_id == 0) {
        return -3;
    }
    return 0;
}

/**
 * @brief Initialize the flash device and enable write access
 */
int32_t PIOS_Flash_Jedec_Init(uintptr_t *flash_id, uint32_t spi_id, uint32_t slave_num)
{
    struct jedec_flash_dev *flash_dev = PIOS_Flash_Jedec_alloc();

    if (!flash_dev) {
        return -1;
    }

    flash_dev->spi_id    = spi_id;
    flash_dev->slave_num = slave_num;
    flash_dev->cfg = NULL;

    (void)PIOS_Flash_Jedec_ReadID(flash_dev);

    for (uint32_t i = 0; i < pios_flash_jedec_catalog_size; ++i) {
        const struct pios_flash_jedec_cfg flash_jedec_entry = pios_flash_jedec_catalog[i];

        if ((flash_dev->manufacturer == flash_jedec_entry.expect_manufacturer)
            && (flash_dev->memorytype == flash_jedec_entry.expect_memorytype)
            && (flash_dev->capacity == flash_jedec_entry.expect_capacity)) {
            flash_dev->cfg = &pios_flash_jedec_catalog[i];
            break;
        }
    }

    if (!flash_dev->cfg) {
        return -1;
    }

    /* Give back a handle to this flash device */
    *flash_id = (uintptr_t)flash_dev;

    return 0;
}


/**
 * @brief Claim the SPI bus for flash use and assert CS pin
 * @return 0 for sucess, -1 for failure to get semaphore
 */
static int32_t PIOS_Flash_Jedec_ClaimBus(struct jedec_flash_dev *flash_dev, bool fast)
{
    if (PIOS_SPI_ClaimBus(flash_dev->spi_id) < 0) {
        return -1;
    }
    PIOS_SPI_SetClockSpeed(flash_dev->spi_id, fast ? FLASH_FAST_PRESCALER : FLASH_PRESCALER);
    PIOS_SPI_RC_PinSet(flash_dev->spi_id, flash_dev->slave_num, 0);
    flash_dev->claimed = true;

    return 0;
}

/**
 * @brief Release the SPI bus sempahore and ensure flash chip not using bus
 */
static int32_t PIOS_Flash_Jedec_ReleaseBus(struct jedec_flash_dev *flash_dev)
{
    PIOS_SPI_RC_PinSet(flash_dev->spi_id, flash_dev->slave_num, 1);
    PIOS_SPI_ReleaseBus(flash_dev->spi_id);
    flash_dev->claimed = false;
    return 0;
}

/**
 * @brief Returns if the flash chip is busy
 * @returns -1 for failure, 0 for not busy, 1 for busy
 */
static int32_t PIOS_Flash_Jedec_Busy(struct jedec_flash_dev *flash_dev)
{
    int32_t status = PIOS_Flash_Jedec_ReadStatus(flash_dev);

    if (status < 0) {
        return -1;
    }
    return status & JEDEC_STATUS_BUSY;
}

/**
 * @brief Execute the write enable instruction and returns the status
 * @returns 0 if successful, -1 if unable to claim bus
 */
static int32_t PIOS_Flash_Jedec_WriteEnable(struct jedec_flash_dev *flash_dev)
{
    if (PIOS_Flash_Jedec_ClaimBus(flash_dev, true) != 0) {
        return -1;
    }

    uint8_t out[] = { JEDEC_WRITE_ENABLE };
    PIOS_SPI_TransferBlock(flash_dev->spi_id, out, NULL, sizeof(out), NULL);
    PIOS_Flash_Jedec_ReleaseBus(flash_dev);

    return 0;
}


/**
 * @brief Read the status register from flash chip and return it
 */
static int32_t PIOS_Flash_Jedec_ReadStatus(struct jedec_flash_dev *flash_dev)
{
    if (PIOS_Flash_Jedec_ClaimBus(flash_dev, true) < 0) {
        return -1;
    }

    uint8_t out[2] = { JEDEC_READ_STATUS, 0 };
    uint8_t in[2]  = { 0, 0 };
    if (PIOS_SPI_TransferBlock(flash_dev->spi_id, out, in, sizeof(out), NULL) < 0) {
        PIOS_Flash_Jedec_ReleaseBus(flash_dev);
        return -2;
    }

    PIOS_Flash_Jedec_ReleaseBus(flash_dev);

    return in[1];
}

/**
 * @brief Read the status register from flash chip and return it
 */
static int32_t PIOS_Flash_Jedec_ReadID(struct jedec_flash_dev *flash_dev)
{
    if (PIOS_Flash_Jedec_ClaimBus(flash_dev, true) < 0) {
        return -2;
    }

    uint8_t out[] = { JEDEC_DEVICE_ID, 0, 0, 0 };
    uint8_t in[4];
    if (PIOS_SPI_TransferBlock(flash_dev->spi_id, out, in, sizeof(out), NULL) < 0) {
        PIOS_Flash_Jedec_ReleaseBus(flash_dev);
        return -3;
    }

    PIOS_Flash_Jedec_ReleaseBus(flash_dev);

    flash_dev->manufacturer = in[1];
    flash_dev->memorytype   = in[2];
    flash_dev->capacity     = in[3];

    return flash_dev->manufacturer;
}

/**********************************
 *
 * Provide a PIOS flash driver API
 *
 *********************************/
#include "pios_flash.h"

#if FLASH_USE_FREERTOS_LOCKS

/**
 * @brief Grab the semaphore to perform a transaction
 * @return 0 for success, -1 for timeout
 */
static int32_t PIOS_Flash_Jedec_StartTransaction(uintptr_t flash_id)
{
    struct jedec_flash_dev *flash_dev = (struct jedec_flash_dev *)flash_id;

    if (PIOS_Flash_Jedec_Validate(flash_dev) != 0) {
        return -1;
    }

#if defined(PIOS_INCLUDE_FREERTOS)
    if (xSemaphoreTake(flash_dev->transaction_lock, portMAX_DELAY) != pdTRUE) {
        return -2;
    }
#endif

    return 0;
}

/**
 * @brief Release the semaphore to perform a transaction
 * @return 0 for success, -1 for timeout
 */
static int32_t PIOS_Flash_Jedec_EndTransaction(uintptr_t flash_id)
{
    struct jedec_flash_dev *flash_dev = (struct jedec_flash_dev *)flash_id;

    if (PIOS_Flash_Jedec_Validate(flash_dev) != 0) {
        return -1;
    }

#if defined(PIOS_INCLUDE_FREERTOS)
    if (xSemaphoreGive(flash_dev->transaction_lock) != pdTRUE) {
        return -2;
    }
#endif

    return 0;
}

#else /* FLASH_USE_FREERTOS_LOCKS */

static int32_t PIOS_Flash_Jedec_StartTransaction(__attribute__((unused)) uintptr_t flash_id)
{
    return 0;
}

static int32_t PIOS_Flash_Jedec_EndTransaction(__attribute__((unused)) uintptr_t flash_id)
{
    return 0;
}

#endif /* FLASH_USE_FREERTOS_LOCKS */

/**
 * @brief Erase a sector on the flash chip
 * @param[in] add Address of flash to erase
 * @returns 0 if successful
 * @retval -1 if unable to claim bus
 * @retval
 */
static int32_t PIOS_Flash_Jedec_EraseSector(uintptr_t flash_id, uint32_t addr)
{
    struct jedec_flash_dev *flash_dev = (struct jedec_flash_dev *)flash_id;

    if (PIOS_Flash_Jedec_Validate(flash_dev) != 0) {
        return -1;
    }

    uint8_t ret;
    uint8_t out[] = { flash_dev->cfg->sector_erase, (addr >> 16) & 0xff, (addr >> 8) & 0xff, addr & 0xff };

    if ((ret = PIOS_Flash_Jedec_WriteEnable(flash_dev)) != 0) {
        return ret;
    }

    if (PIOS_Flash_Jedec_ClaimBus(flash_dev, true) != 0) {
        return -1;
    }

    if (PIOS_SPI_TransferBlock(flash_dev->spi_id, out, NULL, sizeof(out), NULL) < 0) {
        PIOS_Flash_Jedec_ReleaseBus(flash_dev);
        return -2;
    }

    PIOS_Flash_Jedec_ReleaseBus(flash_dev);

    // Keep polling when bus is busy too
    while (PIOS_Flash_Jedec_Busy(flash_dev) != 0) {
#if defined(FLASH_FREERTOS)
        vTaskDelay(2);
#endif
    }

    return 0;
}

/**
 * @brief Execute the whole chip
 * @returns 0 if successful, -1 if unable to claim bus
 */
static int32_t PIOS_Flash_Jedec_EraseChip(uintptr_t flash_id)
{
    struct jedec_flash_dev *flash_dev = (struct jedec_flash_dev *)flash_id;

    if (PIOS_Flash_Jedec_Validate(flash_dev) != 0) {
        return -1;
    }

    uint8_t ret;
    uint8_t out[] = { flash_dev->cfg->chip_erase };

    if ((ret = PIOS_Flash_Jedec_WriteEnable(flash_dev)) != 0) {
        return ret;
    }

    if (PIOS_Flash_Jedec_ClaimBus(flash_dev, true) != 0) {
        return -1;
    }

    if (PIOS_SPI_TransferBlock(flash_dev->spi_id, out, NULL, sizeof(out), NULL) < 0) {
        PIOS_Flash_Jedec_ReleaseBus(flash_dev);
        return -2;
    }

    PIOS_Flash_Jedec_ReleaseBus(flash_dev);

    // Keep polling when bus is busy too
    int i = 0;
    while (PIOS_Flash_Jedec_Busy(flash_dev) != 0) {
#if defined(FLASH_FREERTOS)
        vTaskDelay(1);
        if ((i++) % 100 == 0) {
#else
        if ((i++) % 10000 == 0) {
#endif

#ifdef PIOS_LED_HEARTBEAT
            PIOS_LED_Toggle(PIOS_LED_HEARTBEAT);
#endif
        }
    }

    return 0;
}


/**
 * @brief Write one page of data (up to 256 bytes) aligned to a page start
 * @param[in] addr Address in flash to write to
 * @param[in] data Pointer to data to write to flash
 * @param[in] len Length of data to write (max 256 bytes)
 * @return Zero if success or error code
 * @retval -1 Unable to claim SPI bus
 * @retval -2 Size exceeds 256 bytes
 * @retval -3 Length to write would wrap around page boundary
 */
static int32_t PIOS_Flash_Jedec_WriteData(uintptr_t flash_id, uint32_t addr, uint8_t *data, uint16_t len)
{
    struct jedec_flash_dev *flash_dev = (struct jedec_flash_dev *)flash_id;

    if (PIOS_Flash_Jedec_Validate(flash_dev) != 0) {
        return -1;
    }

    uint8_t ret;
    uint8_t out[4] = { JEDEC_PAGE_WRITE, (addr >> 16) & 0xff, (addr >> 8) & 0xff, addr & 0xff };

    /* Can only write one page at a time */
    if (len > 0x100) {
        return -2;
    }

    /* Ensure number of bytes fits after starting address before end of page */
    if (((addr & 0xff) + len) > 0x100) {
        return -3;
    }
    if ((ret = PIOS_Flash_Jedec_WriteEnable(flash_dev)) != 0) {
        return ret;
    }

    /* Execute write page command and clock in address.  Keep CS asserted */
    if (PIOS_Flash_Jedec_ClaimBus(flash_dev, true) != 0) {
        return -1;
    }
    if (PIOS_SPI_TransferBlock(flash_dev->spi_id, out, NULL, sizeof(out), NULL) < 0) {
        PIOS_Flash_Jedec_ReleaseBus(flash_dev);
        return -1;
    }

    /* Clock out data to flash */
    if (PIOS_SPI_TransferBlock(flash_dev->spi_id, data, NULL, len, NULL) < 0) {
        PIOS_Flash_Jedec_ReleaseBus(flash_dev);
        return -1;
    }

    PIOS_Flash_Jedec_ReleaseBus(flash_dev);

    // Keep polling when bus is busy too
#if defined(FLASH_FREERTOS)
    while (PIOS_Flash_Jedec_Busy(flash_dev) != 0) {
        vTaskDelay(1);
    }
#else

    // Query status this way to prevent accel chip locking us out
    if (PIOS_Flash_Jedec_ClaimBus(flash_dev, true) < 0) {
        return -1;
    }

    PIOS_SPI_TransferByte(flash_dev->spi_id, JEDEC_READ_STATUS);
    while (PIOS_SPI_TransferByte(flash_dev->spi_id, JEDEC_READ_STATUS) & JEDEC_STATUS_BUSY) {
        ;
    }

    PIOS_Flash_Jedec_ReleaseBus(flash_dev);

#endif
    return 0;
}

/**
 * @brief Write multiple chunks of data in one transaction
 * @param[in] addr Address in flash to write to
 * @param[in] data Pointer to data to write to flash
 * @param[in] len Length of data to write (max 256 bytes)
 * @return Zero if success or error code
 * @retval -1 Unable to claim SPI bus
 * @retval -2 Size exceeds 256 bytes
 * @retval -3 Length to write would wrap around page boundary
 */
static int32_t PIOS_Flash_Jedec_WriteChunks(uintptr_t flash_id, uint32_t addr, struct pios_flash_chunk chunks[], uint32_t num)
{
    struct jedec_flash_dev *flash_dev = (struct jedec_flash_dev *)flash_id;

    if (PIOS_Flash_Jedec_Validate(flash_dev) != 0) {
        return -1;
    }

    uint8_t ret;
    uint8_t out[4] = { JEDEC_PAGE_WRITE, (addr >> 16) & 0xff, (addr >> 8) & 0xff, addr & 0xff };

    /* Can only write one page at a time */
    uint32_t len   = 0;
    for (uint32_t i = 0; i < num; i++) {
        len += chunks[i].len;
    }

    if (len > 0x100) {
        return -2;
    }

    /* Ensure number of bytes fits after starting address before end of page */
    if (((addr & 0xff) + len) > 0x100) {
        return -3;
    }
    if ((ret = PIOS_Flash_Jedec_WriteEnable(flash_dev)) != 0) {
        return ret;
    }

    /* Execute write page command and clock in address.  Keep CS asserted */
    if (PIOS_Flash_Jedec_ClaimBus(flash_dev, true) != 0) {
        return -1;
    }

    if (PIOS_SPI_TransferBlock(flash_dev->spi_id, out, NULL, sizeof(out), NULL) < 0) {
        PIOS_Flash_Jedec_ReleaseBus(flash_dev);
        return -1;
    }

    for (uint32_t i = 0; i < num; i++) {
        struct pios_flash_chunk *chunk = &chunks[i];

        /* Clock out data to flash */
        if (PIOS_SPI_TransferBlock(flash_dev->spi_id, chunk->addr, NULL, chunk->len, NULL) < 0) {
            PIOS_Flash_Jedec_ReleaseBus(flash_dev);
            return -1;
        }
    }
    PIOS_Flash_Jedec_ReleaseBus(flash_dev);

    // Skip checking for busy with this to get OS running again fast

    return 0;
}

/**
 * @brief Read data from a location in flash memory
 * @param[in] addr Address in flash to write to
 * @param[in] data Pointer to data to write from flash
 * @param[in] len Length of data to write (max 256 bytes)
 * @return Zero if success or error code
 * @retval -1 Unable to claim SPI bus
 */
static int32_t PIOS_Flash_Jedec_ReadData(uintptr_t flash_id, uint32_t addr, uint8_t *data, uint16_t len)
{
    struct jedec_flash_dev *flash_dev = (struct jedec_flash_dev *)flash_id;

    if (PIOS_Flash_Jedec_Validate(flash_dev) != 0) {
        return -1;
    }
    bool fast_read = flash_dev->cfg->fast_read != 0;
    if (PIOS_Flash_Jedec_ClaimBus(flash_dev, fast_read) == -1) {
        return -1;
    }
    /* Execute read command and clock in address.  Keep CS asserted */
    if (!fast_read) {
        uint8_t out[] = { JEDEC_READ_DATA, (addr >> 16) & 0xff, (addr >> 8) & 0xff, addr & 0xff };
        if (PIOS_SPI_TransferBlock(flash_dev->spi_id, out, NULL, sizeof(out), NULL) < 0) {
            PIOS_Flash_Jedec_ReleaseBus(flash_dev);
            return -2;
        }
    } else {
        uint8_t cmdlen = flash_dev->cfg->fast_read_dummy_bytes + 4;
        uint8_t out[cmdlen];
        memset(out, 0x0, cmdlen);
        out[0] = flash_dev->cfg->fast_read;
        out[1] = (addr >> 16) & 0xff;
        out[2] = (addr >> 8) & 0xff;
        out[3] = addr & 0xff;
        if (PIOS_SPI_TransferBlock(flash_dev->spi_id, out, NULL, cmdlen, NULL) < 0) {
            PIOS_Flash_Jedec_ReleaseBus(flash_dev);
            return -2;
        }
    }

    /* Copy the transfer data to the buffer */
    if (PIOS_SPI_TransferBlock(flash_dev->spi_id, NULL, data, len, NULL) < 0) {
        PIOS_Flash_Jedec_ReleaseBus(flash_dev);
        return -3;
    }

    PIOS_Flash_Jedec_ReleaseBus(flash_dev);

    return 0;
}

/* Provide a flash driver to external drivers */
const struct pios_flash_driver pios_jedec_flash_driver = {
    .start_transaction = PIOS_Flash_Jedec_StartTransaction,
    .end_transaction   = PIOS_Flash_Jedec_EndTransaction,
    .erase_chip   = PIOS_Flash_Jedec_EraseChip,
    .erase_sector = PIOS_Flash_Jedec_EraseSector,
    .write_chunks = PIOS_Flash_Jedec_WriteChunks,
    .write_data   = PIOS_Flash_Jedec_WriteData,
    .read_data    = PIOS_Flash_Jedec_ReadData,
};

#endif /* PIOS_INCLUDE_FLASH */
